The present application relates to generally to wind turbines and particularly to wind turbine blades. More particularly, embodiments of the present application provide methods for manufacturing spar caps using a low viscosity matrix material for optimized technical quality and reduced cost.
Wind power and the use of wind turbines have gained increased attention as the quest for alternative energy sources continues. Wind power may be considered one of the cleanest, most environmentally friendly energy sources presently available. Different from traditional fossil fuel sources, wind power is completely renewable and does not produce noxious or environmentally harmful bi-products. With an increasing attention towards generating more energy from wind power, technological advances in the art have allowed for increased sizes of wind turbines and new designs of wind turbine components. However, as the physical sizes and availability of wind turbines increase, so does the need to balance the cost of manufacturing and operating wind turbines to further allow wind power to be cost-competitive with other energy sources.
A modern wind turbine 10, illustrated in FIG. 1, typically includes a rotor 12 having multiple blades 14 extending therefrom. The rotor 12 is drivingly connected to an electrical generator (not shown) housed within a nacelle 16 atop a tower 18. The blades 14 are exposed to the wind, and capture and transform the kinetic energy of the wind into a rotational motion of the rotor 12 about an axis. The rotational motion is further converted by the electrical generator into electrical energy, which is then fed into the utility grid.
The size, shape, and weight of the blades contribute significantly to the cost and energy efficiencies of wind turbines. An increase in blade size and decrease in blade weight generally increases the energy efficiency of a wind turbine; however, decreasing the blade weight also can result in significantly higher costs due to the increased costs associated with the specialized lightweight materials.
Typically, the spar caps make up approximately one third of the total turbine blade mass. It therefore would be desirable to reduce the weight of the spar cap in order to reduce the weight of the blade, thereby increasing the energy efficiency of the wind turbine. In particular, it would be desirable to increase the composite fiber volume fraction of the spar cap while also increasing the tensile modulus and composite stiffness of the composite material so as to allow for potential reduction in material consumption and blade cost.